Method and apparatus for determining modulation levels that are supported on a channel

Abstract

A logical channel is configured to match a modulation profile of an active channel. A network element is assigned to the logical channel and a ping request is sent to the network element. A response from the network element is measured, such as measuring the MER. The modulation profile is increased in the logical channel and another ping request is sent to the network element. The response is measured again, and the process is repeated until a non-linearity is detected in the response. The acceptable modulation profiles are indicated before the non-linearity is detected in the response.

Description

[0001]This application claims the benefit of U.S. Provisional application 60 / 887,166 filed on Jan. 30, 2007, titled Method To Predict Communications Channel Suitability For Higher Order Modulations, herein incorporated by reference in its entirety.FIELD OF THE INVENTION[0002]This disclosure is directed toward to predicting channel characteristics usable by network elements on a network. More specifically, the disclosure is directed toward determining modulation levels that are supported on an active channel while not impacting existing data services.BACKGROUND OF THE INVENTION[0003]Coaxial cable television systems have been in widespread use for many years and extensive networks have been developed. The extensive and complex networks are often difficult for a cable operator to manage and monitor. A typical cable network generally contains a headend which is usually connected to several nodes which provide content to a cable modem termination system (CMTS) containing several receiver...

AI Technical Summary

Problems solved by technology

The extensive and complex networks are often difficult for a cable operator to manage and monitor.

Any disruption of voice or data traffic is a great inconvenience and often unacceptable to a subscriber.

Clearly the third approach is a poor solution.

The second approach requires longer measurement times due to the long period required to collect a statically significant numbers of packets / bits on which to base a metric and in addition, is subject to the random nature of which network elements are sending data (for example, poor performers might bias the results).

In addition, the second approach requires the network to make errors prior to triggering network changes.

For applications which require error-free or near error-free communications, this is an unacceptable approach.

This approach, however, contains two significant weaknesses: 1) the composite MER reflects the “currently active” cable network elements as measured by data being passed on the upstream, and 2) the composite MER is an average which means that (generally) half the network elements are exhibiting MERs which are lower while many are exhibiting MERs which are higher.

However, if the distribution is wide, and the network operator bases the modulation configuration changes on the average, there is a significant risk that some of the network elements (which are operating at MERs much lower than the channel average) will no longer be able to pass data on such a channel.

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